Conventionally, there has been known a hybrid vehicle which includes a gear transmission mechanism. For example, Patent document 1 has disclosed a technology about a driving device for a hybrid vehicle which includes a gear transmission mechanism configured to transmit a rotation of an internal combustion engine to a power split mechanism through speed change, a first transmission shaft configured to transmit a power from the internal combustion engine to the gear transmission mechanism and a second transmission shaft configured to transmit a power output from the gear transmission mechanism to the power split mechanism. The gear transmission mechanism mentioned in the patent document 1 includes a differential mechanism in which two planetary gear mechanisms are combined, a first brake capable of stopping a rotation of a ring gear R1 of the differential mechanism, a second brake capable of stopping a rotation of a ring gear R2 and a clutch configured to interrupt transmission of power from the first transmission shaft to the ring gear R1.